/**
 * A pub/sub implementation that queues events until a subscriber is added.
 * There is no event name/type, so all events are of the same type.
 *
 * The first subscriber will receive any previously queued events.
 */
export declare class QueuedPubSub<EventData> {
    #private;
    subscribe(handler: (data: EventData) => void): () => void;
    publish(data: EventData): void;
}